1. Field of the Invention
The present invention relates to an aerodynamic noise reduction device which reduces aerodynamic noise originating from a separation region located downstream of a step portion protruding from a surface of an object placed in an airflow.
2. Description of Related Art
There is known, from Japanese Patent Application Laid-open No. 2003-254226, a windmill airflow noise reduction device which is provided with air jet vents near a rear edge portion of each sail of a windmill, and reduces noise by injecting air from the air jet vents to a flow separation region on a surface of the sail.
This windmill airflow noise reduction device injects air from the air jet vents to generate eddies between the sail surface and the separation region with the air flow, and causes these eddies to interfere with eddies in the separation region, so as to encourage a separated airflow to be drawn and reattached to the sail surface. The separation region is thus decreased, reducing the noise.